1. Field of the Invention
The present invention relates to a frame structure for housing panel plates, such as printed circuit boards used in electrical and electronic devices, as well as panel plates for use in other industrial fields, such as panels used as construction materials. More particularly, the invention relates to a frame structure that is capable of readily accommodating variations in the width dimension of the panel plates to be housed.
2. Description of the Prior Art
A prior art frame structure will now be described with reference to FIG. 4. In the frame structure shown in the drawing, a top plate 91 is spaced from and fixed to a bottom plate 92 by four support columns 93. The frame structure also has an immovable side frame board 94 that is erected on either the right or left side, and a movable side frame board 95 that is erected on the other side and can be moved horizontally toward the immovable side frame board 94. In order to secure the movable side frame board 95 at a desired position, sliding frames 98 are disposed between the top plate 91 and the bottom plate 92. The top and bottom plates are each provided with a pair of slots 96 through which are inserted the fastening ends of fastening members 97, such as hexagon-headed bolts or screws, protruded upwardly and downwardly from the sliding frames 98 on the outer side of the movable side frame board 95, that can fasten the frames 98 by engagement with mating members 99, such as nuts or the like. The inner faces of the side frame boards 94 and 95 are provided with a plurality of horizontally extending lateral support grooves 100. Each of a plurality of panel plates 101 can be individually supported horizontally between the side frame boards 94 and 95 by the lateral grooves 100.
The distance between the two side frame boards is adjusted in accordance with the width of the panel plates to be housed. If the distance between the boards is the same as the width of the housed panel plates, however, it becomes difficult to smoothly insert or remove the plates. It is therefore necessary to house the plates with a slight clearance. However, setting this clearance requires fine adjustment of the distance between the side frame boards 94 and 95, which is time-consuming. Moreover, it is not easy to always set the same clearance.
In view of the above, the inventors previously proposed the frame structure shown in FIG. 5 and FIG. 6, which enables the distance between two side frame boards to be adjusted with ease (U.S. Pat. No. 6,328,169).
FIG. 5 is a front view of the frame structure. The frame structure 1 comprises a pair of opposed side frame boards 2 and 3, a pair of bases 4 affixed to the upper ends and lower ends of the pair of side boards 2 and 3, and a pair of connecting plates 5 and 6 that connect the facing sides of the pair of bases 4, thus forming a box-like structure with openings at opposite ends through which panel plates 11 can be housed.
Each of the pair of opposed side frame boards 2 and 3 has a plurality of support grooves 8 formed on its inner surface to receive the panel plates 11. The distance between the facing support grooves 8 can be adjusted using the pair of connecting plates 5 and 6 and anchor means 7, such as screws, for anchoring the pair of connecting plates 5 and 6.
To prevent the panel plate 11 thus housed from falling out of the frame structure, a stop member 9 is provided in the vicinity of the opening at each end thereof. Each of the stop members 9 is supported on the upper and lower bases 4 by means of a hinge member 10.
FIG. 6 is an enlarged view of the lower part of the frame structure 1 of FIG. 5 and illustrates how the spacing between the pair of side frame boards 2 and 3 is set according to the panel plates 11 to be housed. To facilitate understanding, the stop members 9 are not shown. In the drawing, reference symbol E denotes the width of a housed panel plate 11, and symbol D denotes the width to be set, which is greater than width E by a predetermined clearance suitable for readily inserting and removing panel plates.
In order to set the distance between the facing support grooves 8 of the pair of side frame boards 2 and 3 to D, the side frame boards are each provided with a spacing adjustment projection 12 to form the predetermined clearance between the inner surfaces of the side frame boards that face each other. A panel plate 11 to be housed is brought into contact with these projections 12, one of the side frame boards 3 is moved toward the other side frame board 2 made immovable to thereby come into pressure contact with the panel plate 11, and the pair of connecting plates 5 and 6 are anchored with the anchor means 7, such as screws. Employing this operation makes it possible to readily set the spacing between the support grooves 8 of the side frame boards 2 and 3 exactly to the width D with high efficiency.
In the previously proposed frame structure, however, the projections have to be removed after setting of the clearance in order to increase the number of panel plates 11 to be housed.
An object of the present invention is therefore to provide a frame structure that can effectively house panel plates without requiring provision and removal of such projections and can set a distance between sideboards that includes a predetermined clearance with high speed and high precision.
To attain this object, the present invention provides a frame structure that comprises a pair of sideboards facing each other, each sideboard having an inner surface provided with a plurality of support grooves for receiving and supporting panel plates; a first joint for fixing one of the pair of sideboards to a base; and a second joint for fixing the other of the pair of sideboards to the base and provided with a mechanism for effecting movement of the other sideboard toward the one sideboard, the first and second joints having formed on facing inner surfaces thereof at substantially the same height steps for contacting side surfaces of the panel plates and supporting the panel plates, at least one of the steps having a surface for contacting one side surface of one of the panel plates prior to panel plates being received in the plurality of support grooves in order to set a distance between end surfaces of opposed ones of the plurality of support grooves equal to a sum of a width of the panel plates received in and supported by the plurality of support grooves and a predetermined clearance, the at least one surface of the steps projecting inward by the predetermined clearance from the end surfaces of the support grooves of one of the pair of sideboards.
There may be one surface projecting inward by the predetermined clearance from the end surfaces of support grooves of one of the pair of sideboards.
The present invention further provides a frame structure that comprises a pair of sideboards facing each other, each sideboard having an inner surface provided with a plurality of support grooves for receiving and supporting panel plates; first means for fixing one of the pair of sideboards to a base; second means for fixing the other of the pair of sideboards to the base and provided with a mechanism for effecting movement of the other sideboard toward the one sideboard; and an upright wall formed integrally with the base and in front of the one sideboard fixed to the base; the upright wall and second means having formed on facing inner surfaces thereof at substantially the same height steps for contacting side surfaces of the panel plates and supporting the panel plates, the steps having at least one surface for contacting at least one side surface of one of the panel plates prior to the panel plates being received in the plurality of support grooves in order to set a distance between end surfaces of opposed ones of the plurality of support grooves equal to a sum of a width of each of the panel plates received in and supported by the plurality of support grooves and a predetermined clearance, the at least one surface of the steps projecting inward by the predetermined clearance from the end surfaces of the support grooves of one of the pair of sideboards.
Thus, on the first and second joints or on the upright wall and second fixing means, there are formed steps having at least one surface for contacting at least one side surface of one of the panel plates and projecting inward by a predetermined clearance from the end surfaces of the support grooves of one of the pair of sideboards. This eliminates the prior art requirements of providing a projection in a support groove and removing the projection from the support groove. When a panel plate to be housed is placed between the steps and one of the pair of sideboards is moved toward the other sideboard, the distance between the opposed ones of the support grooves becomes the same as the sum of the width of the panel plate and the predetermined clearance.